Specialized coatings are commonly formed over rotor blades, nozzle vanes, combustor parts, and other turbomachine components for protection from rapid degradation within the chemically harsh, high temperature turbomachine environment. The production of such high temperature coatings often entails the deposition of one or more metallic layers over component surfaces having relatively complex geometries, such as the aerodynamically-streamlined pressure and suction sides of a rotor blade or nozzle vane. Traditionally, CVD, pack cementation, APS, and similar processes have been employed to deposit the metallic layers utilized to produce such high temperature coatings. More recently, however, ionic liquid bath plating processes have emerged as a viable alternative to such conventional deposition processes. Advantageously, ionic liquid bath plating processes are well-suited for depositing metallic layers, including aluminum-containing metallic layers utilized in the production of MCrAlY bond coats, aluminide coatings, and platinum-aluminide, over metallic components having relatively complex geometries. Additionally, ionic liquid bath plating processes can be performed at relatively low processing temperatures to mitigate high temperature masking requirements often associated with conventional deposition processes.
While providing the above-noted advantages, ionic liquid bath plating processes remain limited in several respects. Ionic liquid bath plating solutions are often costly, and, in certain cases, may cost in excess of 100,000 USD when obtained in sufficient volume to fill a conventional large capacity (e.g., 100 gallon) plating solution bath. Such plating solutions are typically non-aqueous and highly sensitive to water contamination, with plating performance degradation potentially occurring with exposure to moisture contained in the ambient air. The throwing power and electrical conductivity within the ionic liquid plating solution bath is often relatively poor. As a result, it may be desirable or necessary to position the turbomachine components (or other workpieces) to be plated immediately adjacent the plating anodes in a highly precise, non-contacting relationship. Finally, as a still further limitation, the plating anodes utilized in ionic liquid bath plating must typically remain within the plating solution bath after anode activation. Thus, when multiple anodes are utilized to plate multiple workpieces in parallel utilizing an open bath plating setup, replacement or reinsertion of individual plating anodes may necessitate shutdown of the entire plating system shutdown adding undesired cost and delay to the plating process.
There thus exists an ongoing need for improved ionic liquid bath plating systems and methods, which overcome one or more of the limitations set-forth above. Ideally, such ionic liquid bath plating systems and methods would be well-suited for usage in depositing metallic (e.g., aluminum-containing) layers onto the contoured surface of turbomachine components including, for example, rotor blades, nozzle vanes, and turbomachine components containing multiple airfoils at the time of plating, such as bladed GTE rotors and turbine nozzles. Similarly, it would be desirable to provide anodes facilitating the deposition of metallic layers onto airfoil-containing turbomachine components utilizing such ionic liquid bath plating processes. Other desirable features and characteristics of embodiments of the present invention will become apparent from the subsequent Detailed Description and the appended Claims, taken in conjunction with the accompanying drawings and the foregoing Background.